18 #define logevent(s) { logevent(s); \
19 if (!(flags & FLAG_CONNECTION) && (flags & FLAG_VERBOSE)) \
20 fprintf(stderr, "%s\n", s); }
22 #define SSH1_MSG_DISCONNECT 1
23 #define SSH1_SMSG_PUBLIC_KEY 2
24 #define SSH1_CMSG_SESSION_KEY 3
25 #define SSH1_CMSG_USER 4
26 #define SSH1_CMSG_AUTH_RSA 6
27 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7
28 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8
29 #define SSH1_CMSG_AUTH_PASSWORD 9
30 #define SSH1_CMSG_REQUEST_PTY 10
31 #define SSH1_CMSG_WINDOW_SIZE 11
32 #define SSH1_CMSG_EXEC_SHELL 12
33 #define SSH1_CMSG_EXEC_CMD 13
34 #define SSH1_SMSG_SUCCESS 14
35 #define SSH1_SMSG_FAILURE 15
36 #define SSH1_CMSG_STDIN_DATA 16
37 #define SSH1_SMSG_STDOUT_DATA 17
38 #define SSH1_SMSG_STDERR_DATA 18
39 #define SSH1_CMSG_EOF 19
40 #define SSH1_SMSG_EXIT_STATUS 20
41 #define SSH1_CMSG_EXIT_CONFIRMATION 33
42 #define SSH1_MSG_IGNORE 32
43 #define SSH1_MSG_DEBUG 36
44 #define SSH1_CMSG_AUTH_TIS 39
45 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40
46 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41
48 #define SSH1_AUTH_TIS 5
50 #define SSH2_MSG_DISCONNECT 1
51 #define SSH2_MSG_IGNORE 2
52 #define SSH2_MSG_UNIMPLEMENTED 3
53 #define SSH2_MSG_DEBUG 4
54 #define SSH2_MSG_SERVICE_REQUEST 5
55 #define SSH2_MSG_SERVICE_ACCEPT 6
56 #define SSH2_MSG_KEXINIT 20
57 #define SSH2_MSG_NEWKEYS 21
58 #define SSH2_MSG_KEXDH_INIT 30
59 #define SSH2_MSG_KEXDH_REPLY 31
60 #define SSH2_MSG_USERAUTH_REQUEST 50
61 #define SSH2_MSG_USERAUTH_FAILURE 51
62 #define SSH2_MSG_USERAUTH_SUCCESS 52
63 #define SSH2_MSG_USERAUTH_BANNER 53
64 #define SSH2_MSG_USERAUTH_PK_OK 60
65 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60
66 #define SSH2_MSG_GLOBAL_REQUEST 80
67 #define SSH2_MSG_REQUEST_SUCCESS 81
68 #define SSH2_MSG_REQUEST_FAILURE 82
69 #define SSH2_MSG_CHANNEL_OPEN 90
70 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91
71 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92
72 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93
73 #define SSH2_MSG_CHANNEL_DATA 94
74 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95
75 #define SSH2_MSG_CHANNEL_EOF 96
76 #define SSH2_MSG_CHANNEL_CLOSE 97
77 #define SSH2_MSG_CHANNEL_REQUEST 98
78 #define SSH2_MSG_CHANNEL_SUCCESS 99
79 #define SSH2_MSG_CHANNEL_FAILURE 100
81 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1
82 #define SSH2_OPEN_CONNECT_FAILED 2
83 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3
84 #define SSH2_OPEN_RESOURCE_SHORTAGE 4
85 #define SSH2_EXTENDED_DATA_STDERR 1
87 #define GET_32BIT(cp) \
88 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
89 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
90 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
91 ((unsigned long)(unsigned char)(cp)[3]))
93 #define PUT_32BIT(cp, value) { \
94 (cp)[0] = (unsigned char)((value) >> 24); \
95 (cp)[1] = (unsigned char)((value) >> 16); \
96 (cp)[2] = (unsigned char)((value) >> 8); \
97 (cp)[3] = (unsigned char)(value); }
99 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
101 /* Coroutine mechanics for the sillier bits of the code */
102 #define crBegin1 static int crLine = 0;
103 #define crBegin2 switch(crLine) { case 0:;
104 #define crBegin crBegin1; crBegin2;
105 #define crFinish(z) } crLine = 0; return (z)
106 #define crFinishV } crLine = 0; return
107 #define crReturn(z) \
109 crLine=__LINE__; return (z); case __LINE__:;\
113 crLine=__LINE__; return; case __LINE__:;\
115 #define crStop(z) do{ crLine = 0; return (z); }while(0)
116 #define crStopV do{ crLine = 0; return; }while(0)
117 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
118 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
120 extern struct ssh_cipher ssh_3des
;
121 extern struct ssh_cipher ssh_3des_ssh2
;
122 extern struct ssh_cipher ssh_des
;
123 extern struct ssh_cipher ssh_blowfish
;
125 /* for ssh 2; we miss out single-DES because it isn't supported */
126 struct ssh_cipher
*ciphers
[] = { &ssh_3des_ssh2
, &ssh_blowfish
};
128 extern struct ssh_kex ssh_diffiehellman
;
129 struct ssh_kex
*kex_algs
[] = { &ssh_diffiehellman
};
131 extern struct ssh_hostkey ssh_dss
;
132 struct ssh_hostkey
*hostkey_algs
[] = { &ssh_dss
};
134 extern struct ssh_mac ssh_sha1
;
138 static void nullmac_key(unsigned char *key
) { }
139 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
140 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
141 struct ssh_mac ssh_mac_none
= {
142 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
144 struct ssh_mac
*macs
[] = { &ssh_sha1
, &ssh_mac_none
};
146 struct ssh_compress ssh_comp_none
= {
149 struct ssh_compress
*compressions
[] = { &ssh_comp_none
};
151 static SOCKET s
= INVALID_SOCKET
;
153 static unsigned char session_key
[32];
154 static struct ssh_cipher
*cipher
= NULL
;
155 static struct ssh_cipher
*cscipher
= NULL
;
156 static struct ssh_cipher
*sccipher
= NULL
;
157 static struct ssh_mac
*csmac
= NULL
;
158 static struct ssh_mac
*scmac
= NULL
;
159 static struct ssh_compress
*cscomp
= NULL
;
160 static struct ssh_compress
*sccomp
= NULL
;
161 static struct ssh_kex
*kex
= NULL
;
162 static struct ssh_hostkey
*hostkey
= NULL
;
163 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
165 static char *savedhost
;
168 SSH_STATE_BEFORE_SIZE
,
172 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
174 static int size_needed
= FALSE
;
176 static void s_write (char *buf
, int len
) {
178 int i
= send (s
, buf
, len
, 0);
181 fatalbox("Lost connection while sending");
187 static int s_read (char *buf
, int len
) {
190 int i
= recv (s
, buf
, len
, 0);
193 len
-= i
, buf
+= i
, ret
+= i
;
200 static void c_write (char *buf
, int len
) {
201 if (!(flags
& FLAG_CONNECTION
)) {
203 for (i
= 0; i
< len
; i
++)
205 fputc(buf
[i
], stderr
);
221 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
222 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
224 static int ssh_version
;
225 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
226 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
227 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
228 static void ssh_size(void);
230 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
233 * Collect incoming data in the incoming packet buffer.
234 * Decipher and verify the packet when it is completely read.
235 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
236 * Update the *data and *datalen variables.
237 * Return the additional nr of bytes needed, or 0 when
238 * a complete packet is available.
240 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
242 static long len
, pad
, biglen
, to_read
;
243 static unsigned long realcrc
, gotcrc
;
244 static unsigned char *p
;
254 for (i
= len
= 0; i
< 4; i
++) {
255 while ((*datalen
) == 0)
257 len
= (len
<< 8) + **data
;
258 (*data
)++, (*datalen
)--;
262 if (len
== 0x52656d6f) { /* "Remo"te server has closed ... */
263 len
= 0x300; /* big enough to carry to end */
269 pktin
.length
= len
- 5;
271 if (pktin
.maxlen
< biglen
) {
272 pktin
.maxlen
= biglen
;
273 pktin
.data
= (pktin
.data
== NULL ?
malloc(biglen
+APIEXTRA
) :
274 realloc(pktin
.data
, biglen
+APIEXTRA
));
276 fatalbox("Out of memory");
281 while (to_read
> 0) {
284 while ((*datalen
) == 0)
286 if (chunk
> (*datalen
))
288 memcpy(p
, *data
, chunk
);
296 cipher
->decrypt(pktin
.data
, biglen
);
298 pktin
.type
= pktin
.data
[pad
];
299 pktin
.body
= pktin
.data
+ pad
+ 1;
301 realcrc
= crc32(pktin
.data
, biglen
-4);
302 gotcrc
= GET_32BIT(pktin
.data
+biglen
-4);
303 if (gotcrc
!= realcrc
) {
304 fatalbox("Incorrect CRC received on packet");
307 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
308 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
309 pktin
.type
== SSH1_MSG_DEBUG
||
310 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
311 long strlen
= GET_32BIT(pktin
.body
);
312 if (strlen
+ 4 != pktin
.length
)
313 fatalbox("Received data packet with bogus string length");
316 if (pktin
.type
== SSH1_MSG_DEBUG
) {
317 /* log debug message */
319 int strlen
= GET_32BIT(pktin
.body
);
320 strcpy(buf
, "Remote: ");
321 if (strlen
> 70) strlen
= 70;
322 memcpy(buf
+8, pktin
.body
+4, strlen
);
323 buf
[8+strlen
] = '\0';
326 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
334 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
336 static long len
, pad
, payload
, packetlen
, maclen
;
338 static int cipherblk
;
339 static unsigned long incoming_sequence
= 0;
349 cipherblk
= cipher
->blksize
;
355 if (pktin
.maxlen
< cipherblk
) {
356 pktin
.maxlen
= cipherblk
;
357 pktin
.data
= (pktin
.data
== NULL ?
malloc(cipherblk
+APIEXTRA
) :
358 realloc(pktin
.data
, cipherblk
+APIEXTRA
));
360 fatalbox("Out of memory");
364 * Acquire and decrypt the first block of the packet. This will
365 * contain the length and padding details.
367 for (i
= len
= 0; i
< cipherblk
; i
++) {
368 while ((*datalen
) == 0)
369 crReturn(cipherblk
-i
);
370 pktin
.data
[i
] = *(*data
)++;
374 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
379 sccipher
->decrypt(pktin
.data
, cipherblk
);
382 * Now get the length and padding figures.
384 len
= GET_32BIT(pktin
.data
);
388 * This enables us to deduce the payload length.
390 payload
= len
- pad
- 1;
392 pktin
.length
= payload
+ 5;
395 * So now we can work out the total packet length.
398 maclen
= scmac ? scmac
->len
: 0;
401 * Adjust memory allocation if packet is too big.
403 if (pktin
.maxlen
< packetlen
) {
404 pktin
.maxlen
= packetlen
;
405 pktin
.data
= (pktin
.data
== NULL ?
malloc(packetlen
+APIEXTRA
) :
406 realloc(pktin
.data
, packetlen
+APIEXTRA
));
408 fatalbox("Out of memory");
412 * Read and decrypt the remainder of the packet.
414 for (i
= cipherblk
; i
< packetlen
+ maclen
; i
++) {
415 while ((*datalen
) == 0)
416 crReturn(packetlen
+ maclen
- i
);
417 pktin
.data
[i
] = *(*data
)++;
420 /* Decrypt everything _except_ the MAC. */
422 sccipher
->decrypt(pktin
.data
+ cipherblk
, packetlen
- cipherblk
);
425 debug(("Got packet len=%d pad=%d\r\n", len
, pad
));
426 for (i
= 0; i
< packetlen
; i
++)
427 debug((" %02x", (unsigned char)pktin
.data
[i
]));
434 if (scmac
&& !scmac
->verify(pktin
.data
, len
+4, incoming_sequence
))
435 fatalbox("Incorrect MAC received on packet");
436 incoming_sequence
++; /* whether or not we MACed */
439 pktin
.type
= pktin
.data
[5];
441 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
442 goto next_packet
; /* FIXME: print DEBUG message */
447 static void ssh_gotdata(unsigned char *data
, int datalen
)
449 while (datalen
> 0) {
450 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
451 ssh_protocol(NULL
, 0, 1);
452 if (ssh_state
== SSH_STATE_CLOSED
) {
460 static void s_wrpkt_start(int type
, int len
) {
463 len
+= 5; /* type and CRC */
467 pktout
.length
= len
-5;
468 if (pktout
.maxlen
< biglen
) {
469 pktout
.maxlen
= biglen
;
471 /* Allocate enough buffer space for extra block
472 * for MS CryptEncrypt() */
473 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
474 realloc(pktout
.data
, biglen
+12));
476 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
477 realloc(pktout
.data
, biglen
+4));
480 fatalbox("Out of memory");
484 pktout
.body
= pktout
.data
+4+pad
+1;
487 static void s_wrpkt(void) {
488 int pad
, len
, biglen
, i
;
491 len
= pktout
.length
+ 5; /* type and CRC */
495 pktout
.body
[-1] = pktout
.type
;
496 for (i
=0; i
<pad
; i
++)
497 pktout
.data
[i
+4] = random_byte();
498 crc
= crc32(pktout
.data
+4, biglen
-4);
499 PUT_32BIT(pktout
.data
+biglen
, crc
);
500 PUT_32BIT(pktout
.data
, len
);
503 cipher
->encrypt(pktout
.data
+4, biglen
);
505 s_write(pktout
.data
, biglen
+4);
509 * Construct a packet with the specified contents and
510 * send it to the server.
512 static void send_packet(int pkttype
, ...)
515 unsigned char *p
, *argp
, argchar
;
516 unsigned long argint
;
517 int pktlen
, argtype
, arglen
;
522 va_start(args
, pkttype
);
523 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
526 (void) va_arg(args
, int);
530 (void) va_arg(args
, char);
534 (void) va_arg(args
, unsigned char *);
535 arglen
= va_arg(args
, int);
539 argp
= va_arg(args
, unsigned char *);
540 arglen
= strlen(argp
);
541 pktlen
+= 4 + arglen
;
544 bn
= va_arg(args
, Bignum
);
546 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
548 pktlen
+= 2 + (i
+7)/8;
556 s_wrpkt_start(pkttype
, pktlen
);
559 va_start(args
, pkttype
);
560 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
563 argint
= va_arg(args
, int);
564 PUT_32BIT(p
, argint
);
568 argchar
= va_arg(args
, unsigned char);
573 argp
= va_arg(args
, unsigned char *);
574 arglen
= va_arg(args
, int);
575 memcpy(p
, argp
, arglen
);
579 argp
= va_arg(args
, unsigned char *);
580 arglen
= strlen(argp
);
581 PUT_32BIT(p
, arglen
);
582 memcpy(p
+ 4, argp
, arglen
);
586 bn
= va_arg(args
, Bignum
);
588 while ( i
> 0 && (bn
[i
/16+1] >> (i
%16)) == 0 )
590 *p
++ = (i
>> 8) & 0xFF;
595 *p
++ = bn
[i
/2+1] >> 8;
597 *p
++ = bn
[i
/2+1] & 0xFF;
609 * Connect to specified host and port.
610 * Returns an error message, or NULL on success.
611 * Also places the canonical host name into `realhost'.
613 static char *connect_to_host(char *host
, int port
, char **realhost
)
623 savedhost
= malloc(1+strlen(host
));
625 fatalbox("Out of memory");
626 strcpy(savedhost
, host
);
629 port
= 22; /* default ssh port */
641 if ( (a
= inet_addr(host
)) == (unsigned long) INADDR_NONE
) {
642 if ( (h
= gethostbyname(host
)) == NULL
)
643 switch (WSAGetLastError()) {
644 case WSAENETDOWN
: return "Network is down";
645 case WSAHOST_NOT_FOUND
: case WSANO_DATA
:
646 return "Host does not exist";
647 case WSATRY_AGAIN
: return "Host not found";
648 default: return "gethostbyname: unknown error";
650 memcpy (&a
, h
->h_addr
, sizeof(a
));
651 *realhost
= h
->h_name
;
662 s
= socket(AF_INET
, SOCK_STREAM
, 0);
663 if (s
== INVALID_SOCKET
)
664 switch (WSAGetLastError()) {
665 case WSAENETDOWN
: return "Network is down";
666 case WSAEAFNOSUPPORT
: return "TCP/IP support not present";
667 default: return "socket(): unknown error";
671 * Bind to local address.
673 addr
.sin_family
= AF_INET
;
674 addr
.sin_addr
.s_addr
= htonl(INADDR_ANY
);
675 addr
.sin_port
= htons(0);
676 if (bind (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
677 switch (WSAGetLastError()) {
678 case WSAENETDOWN
: return "Network is down";
679 default: return "bind(): unknown error";
683 * Connect to remote address.
685 addr
.sin_addr
.s_addr
= htonl(a
);
686 addr
.sin_port
= htons((short)port
);
687 if (connect (s
, (struct sockaddr
*)&addr
, sizeof(addr
)) == SOCKET_ERROR
)
688 switch (WSAGetLastError()) {
689 case WSAENETDOWN
: return "Network is down";
690 case WSAECONNREFUSED
: return "Connection refused";
691 case WSAENETUNREACH
: return "Network is unreachable";
692 case WSAEHOSTUNREACH
: return "No route to host";
693 default: return "connect(): unknown error";
697 send(s
, "connect ", 8, 0);
698 send(s
, FWhost
, strlen(FWhost
), 0);
701 sprintf(buf
, " %d\n", FWport
);
702 send (s
, buf
, strlen(buf
), 0);
709 static int ssh_versioncmp(char *a
, char *b
) {
711 unsigned long av
, bv
;
713 av
= strtoul(a
, &ae
, 10);
714 bv
= strtoul(b
, &be
, 10);
715 if (av
!= bv
) return (av
< bv ?
-1 : +1);
716 if (*ae
== '.') ae
++;
717 if (*be
== '.') be
++;
718 av
= strtoul(ae
, &ae
, 10);
719 bv
= strtoul(be
, &be
, 10);
720 if (av
!= bv
) return (av
< bv ?
-1 : +1);
726 * Utility routine for putting an SSH-protocol `string' into a SHA
730 void sha_string(SHA_State
*s
, void *str
, int len
) {
731 unsigned char lenblk
[4];
733 PUT_32BIT(lenblk
, len
);
734 if (!fp
) fp
= fopen("h:\\statham\\windows\\putty\\data","wb");
735 fwrite(lenblk
, 4, 1, fp
);
736 SHA_Bytes(s
, lenblk
, 4);
737 fwrite(str
, len
, 1, fp
);
739 SHA_Bytes(s
, str
, len
);
743 * SSH2 packet construction functions.
745 void ssh2_pkt_adddata(void *data
, int len
) {
746 pktout
.length
+= len
;
747 if (pktout
.maxlen
< pktout
.length
) {
748 pktout
.maxlen
= pktout
.length
+ 256;
749 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
750 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
752 fatalbox("Out of memory");
754 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
756 void ssh2_pkt_addbyte(unsigned char byte
) {
757 ssh2_pkt_adddata(&byte
, 1);
759 void ssh2_pkt_init(int pkt_type
) {
761 ssh2_pkt_addbyte((unsigned char)pkt_type
);
763 void ssh2_pkt_addbool(unsigned char value
) {
764 ssh2_pkt_adddata(&value
, 1);
766 void ssh2_pkt_adduint32(unsigned long value
) {
769 ssh2_pkt_adddata(x
, 4);
771 void ssh2_pkt_addstring_start(void) {
772 ssh2_pkt_adduint32(0);
773 pktout
.savedpos
= pktout
.length
;
775 void ssh2_pkt_addstring_str(char *data
) {
776 ssh2_pkt_adddata(data
, strlen(data
));
777 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
778 pktout
.length
- pktout
.savedpos
);
780 void ssh2_pkt_addstring_data(char *data
, int len
) {
781 ssh2_pkt_adddata(data
, len
);
782 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
783 pktout
.length
- pktout
.savedpos
);
785 void ssh2_pkt_addstring(char *data
) {
786 ssh2_pkt_addstring_start();
787 ssh2_pkt_addstring_str(data
);
789 char *ssh2_mpint_fmt(Bignum b
, int *len
) {
792 p
= malloc(n
* 2 + 1);
794 fatalbox("out of memory");
796 for (i
= 0; i
< n
; i
++) {
797 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
798 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
801 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
803 memmove(p
, p
+i
, n
*2+1-i
);
807 void ssh2_pkt_addmp(Bignum b
) {
810 p
= ssh2_mpint_fmt(b
, &len
);
811 ssh2_pkt_addstring_start();
812 ssh2_pkt_addstring_data(p
, len
);
815 void ssh2_pkt_send(void) {
816 int cipherblk
, maclen
, padding
, i
;
817 static unsigned long outgoing_sequence
= 0;
820 * Add padding. At least four bytes, and must also bring total
821 * length (minus MAC) up to a multiple of the block size.
823 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
824 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
826 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
827 pktout
.data
[4] = padding
;
828 for (i
= 0; i
< padding
; i
++)
829 pktout
.data
[pktout
.length
+ i
] = random_byte();
830 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
832 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
834 outgoing_sequence
++; /* whether or not we MACed */
837 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
838 for (i
= 0; i
< pktout
.length
+padding
; i
++)
839 debug((" %02x", (unsigned char)pktout
.data
[i
]));
844 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
845 maclen
= csmac ? csmac
->len
: 0;
847 s_write(pktout
.data
, pktout
.length
+ padding
+ maclen
);
851 void bndebug(char *string
, Bignum b
) {
854 p
= ssh2_mpint_fmt(b
, &len
);
855 debug(("%s", string
));
856 for (i
= 0; i
< len
; i
++)
857 debug((" %02x", p
[i
]));
863 void sha_mpint(SHA_State
*s
, Bignum b
) {
866 p
= ssh2_mpint_fmt(b
, &len
);
867 sha_string(s
, p
, len
);
872 * SSH2 packet decode functions.
874 unsigned long ssh2_pkt_getuint32(void) {
876 if (pktin
.length
- pktin
.savedpos
< 4)
877 return 0; /* arrgh, no way to decline (FIXME?) */
878 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
882 void ssh2_pkt_getstring(char **p
, int *length
) {
884 if (pktin
.length
- pktin
.savedpos
< 4)
886 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
888 if (pktin
.length
- pktin
.savedpos
< *length
)
890 *p
= pktin
.data
+pktin
.savedpos
;
891 pktin
.savedpos
+= *length
;
893 Bignum
ssh2_pkt_getmp(void) {
898 ssh2_pkt_getstring(&p
, &length
);
902 fatalbox("internal error: Can't handle negative mpints");
903 b
= newbn((length
+1)/2);
904 for (i
= 0; i
< length
; i
++) {
907 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
909 b
[j
/2+1] |= ((unsigned char)p
[i
]);
914 static int do_ssh_init(void) {
918 char vlog
[sizeof(vstring
)+20];
923 while (s_read(&c
, 1) == 1) {
924 if (c
== 'S' && i
< 2) i
++;
925 else if (c
== 'S' && i
== 2) i
= 2;
926 else if (c
== 'H' && i
== 2) break;
930 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
931 if (s_read(&c
,1) != 1 || c
!= 'S') return 0;
932 if (s_read(&c
,1) != 1 || c
!= 'H') return 0;
934 strcpy(vstring
, "SSH-");
936 if (s_read(&c
,1) != 1 || c
!= '-') return 0;
939 if (s_read(&c
,1) != 1)
941 if (vsp
< vstring
+sizeof(vstring
)-1)
947 } else if (i
< sizeof(version
)-1)
955 sprintf(vlog
, "Server version: %s", vstring
);
956 vlog
[strcspn(vlog
, "\r\n")] = '\0';
959 if (ssh_versioncmp(version
, "2.0" /* FIXME: "1.99" */ ) >= 0) {
961 * This is a v2 server. Begin v2 protocol.
963 char *verstring
= "SSH-2.0-PuTTY";
966 * Hash our version string and their version string.
968 sha_string(&exhash
, verstring
, strlen(verstring
));
969 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
970 sprintf(vstring
, "%s\n", verstring
);
971 sprintf(vlog
, "We claim version: %s", verstring
);
973 logevent("Using SSH protocol version 2");
974 s_write(vstring
, strlen(vstring
));
975 ssh_protocol
= ssh2_protocol
;
977 s_rdpkt
= ssh2_rdpkt
;
980 * This is a v1 server. Begin v1 protocol.
982 sprintf(vstring
, "SSH-%s-PuTTY\n",
983 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
984 sprintf(vlog
, "We claim version: %s", vstring
);
985 vlog
[strcspn(vlog
, "\r\n")] = '\0';
987 logevent("Using SSH protocol version 1");
988 s_write(vstring
, strlen(vstring
));
989 ssh_protocol
= ssh1_protocol
;
991 s_rdpkt
= ssh1_rdpkt
;
997 * Handle the key exchange and user authentication phases.
999 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1002 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1003 unsigned char cookie
[8];
1004 struct RSAKey servkey
, hostkey
;
1005 struct MD5Context md5c
;
1006 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1007 static int tried_publickey
;
1008 static unsigned char session_id
[16];
1013 if (!ispkt
) crWaitUntil(ispkt
);
1015 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
)
1016 fatalbox("Public key packet not received");
1018 logevent("Received public keys");
1020 memcpy(cookie
, pktin
.body
, 8);
1022 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1023 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1026 * Hash the host key and print the hash in the log box. Just as
1027 * a last resort in case the registry's host key checking is
1028 * compromised, we'll allow the user some ability to verify
1032 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1033 MD5Final(session_id
, &md5c
);
1037 logevent("Host key MD5 is:");
1038 strcpy(logmsg
, " ");
1039 for (i
= 0; i
< 16; i
++)
1040 sprintf(logmsg
+strlen(logmsg
), "%02x", session_id
[i
]);
1044 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1045 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1048 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1049 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1050 MD5Update(&md5c
, pktin
.body
, 8);
1051 MD5Final(session_id
, &md5c
);
1053 for (i
=0; i
<32; i
++)
1054 session_key
[i
] = random_byte();
1056 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1058 rsabuf
= malloc(len
);
1060 fatalbox("Out of memory");
1063 * Verify the host key.
1067 * First format the key into a string.
1069 int len
= rsastr_len(&hostkey
);
1070 char *keystr
= malloc(len
);
1072 fatalbox("Out of memory");
1073 rsastr_fmt(keystr
, &hostkey
);
1074 verify_ssh_host_key(savedhost
, keystr
);
1078 for (i
=0; i
<32; i
++) {
1079 rsabuf
[i
] = session_key
[i
];
1081 rsabuf
[i
] ^= session_id
[i
];
1084 if (hostkey
.bytes
> servkey
.bytes
) {
1085 rsaencrypt(rsabuf
, 32, &servkey
);
1086 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1088 rsaencrypt(rsabuf
, 32, &hostkey
);
1089 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1092 logevent("Encrypted session key");
1094 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1095 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1097 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1098 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1099 cipher_type
= SSH_CIPHER_3DES
;
1101 switch (cipher_type
) {
1102 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1103 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1104 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1107 send_packet(SSH1_CMSG_SESSION_KEY
,
1108 PKT_CHAR
, cipher_type
,
1109 PKT_DATA
, cookie
, 8,
1110 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1111 PKT_DATA
, rsabuf
, len
,
1115 logevent("Trying to enable encryption...");
1119 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish
:
1120 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1122 cipher
->sesskey(session_key
);
1126 if (pktin
.type
!= SSH1_SMSG_SUCCESS
)
1127 fatalbox("Encryption not successfully enabled");
1129 logevent("Successfully started encryption");
1133 static char username
[100];
1136 if (!(flags
& FLAG_CONNECTION
) && !*cfg
.username
) {
1137 c_write("login as: ", 10);
1139 crWaitUntil(!ispkt
);
1140 while (inlen
--) switch (c
= *in
++) {
1147 c_write("\b \b", 3);
1153 c_write("\b \b", 3);
1162 if (((c
>= ' ' && c
<= '~') ||
1163 ((unsigned char)c
>= 160)) && pos
< 40) {
1164 username
[pos
++] = c
;
1171 username
[strcspn(username
, "\n\r")] = '\0';
1174 strncpy(username
, cfg
.username
, 99);
1175 username
[99] = '\0';
1176 if (flags
& FLAG_VERBOSE
) {
1177 sprintf(stuff
, "Sent username \"%s\".\r\n", username
);
1178 c_write(stuff
, strlen(stuff
));
1182 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1184 char userlog
[20+sizeof(username
)];
1185 sprintf(userlog
, "Sent username \"%s\"", username
);
1192 tried_publickey
= 0;
1194 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1195 static char password
[100];
1198 static int pwpkt_type
;
1200 * Show password prompt, having first obtained it via a TIS
1201 * exchange if we're doing TIS authentication.
1203 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1204 if (*cfg
.keyfile
&& !tried_publickey
)
1205 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1207 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
&& !FLAG_WINDOWED
) {
1209 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1210 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1212 * get_password failed to get a password (for
1213 * example because one was supplied on the command
1214 * line which has already failed to work).
1217 logevent("No more passwords to try");
1218 ssh_state
= SSH_STATE_CLOSED
;
1223 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1225 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1226 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1227 logevent("Requested TIS authentication");
1228 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1230 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1231 logevent("TIS authentication declined");
1232 c_write("TIS authentication refused.\r\n", 29);
1234 int challengelen
= ((pktin
.body
[0] << 24) |
1235 (pktin
.body
[1] << 16) |
1236 (pktin
.body
[2] << 8) |
1238 logevent("Received TIS challenge");
1239 c_write(pktin
.body
+4, challengelen
);
1242 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
)
1243 c_write("password: ", 10);
1244 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1245 if (flags
& FLAG_VERBOSE
)
1246 c_write("Trying public key authentication.\r\n", 35);
1247 if (!rsakey_encrypted(cfg
.keyfile
)) {
1248 if (flags
& FLAG_VERBOSE
)
1249 c_write("No passphrase required.\r\n", 25);
1252 c_write("passphrase: ", 12);
1257 crWaitUntil(!ispkt
);
1258 while (inlen
--) switch (c
= *in
++) {
1275 if (((c
>= ' ' && c
<= '~') ||
1276 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1277 password
[pos
++] = c
;
1286 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1288 * Try public key authentication with the specified
1291 static struct RSAKey pubkey
;
1292 static Bignum challenge
, response
;
1294 static unsigned char buffer
[32];
1296 tried_publickey
= 1;
1297 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
1299 c_write("Couldn't load public key from ", 30);
1300 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1301 c_write(".\r\n", 3);
1302 continue; /* go and try password */
1305 c_write("Wrong passphrase.\r\n", 19);
1306 tried_publickey
= 0;
1307 continue; /* try again */
1311 * Send a public key attempt.
1313 send_packet(SSH1_CMSG_AUTH_RSA
,
1314 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1317 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1318 if (flags
& FLAG_VERBOSE
)
1319 c_write("Server refused our public key.\r\n", 32);
1320 continue; /* go and try password */
1322 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
)
1323 fatalbox("Bizarre response to offer of public key");
1324 ssh1_read_bignum(pktin
.body
, &challenge
);
1325 response
= rsadecrypt(challenge
, &pubkey
);
1326 freebn(pubkey
.private_exponent
); /* burn the evidence */
1328 for (i
= 0; i
< 32; i
+= 2) {
1329 buffer
[i
] = response
[16-i
/2] >> 8;
1330 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1334 MD5Update(&md5c
, buffer
, 32);
1335 MD5Update(&md5c
, session_id
, 16);
1336 MD5Final(buffer
, &md5c
);
1338 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1339 PKT_DATA
, buffer
, 16, PKT_END
);
1342 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1343 if (flags
& FLAG_VERBOSE
)
1344 c_write("Failed to authenticate with our public key.\r\n",
1346 continue; /* go and try password */
1347 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1348 fatalbox("Bizarre response to RSA authentication response");
1351 break; /* we're through! */
1353 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1355 logevent("Sent password");
1356 memset(password
, 0, strlen(password
));
1358 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1359 if (flags
& FLAG_VERBOSE
)
1360 c_write("Access denied\r\n", 15);
1361 logevent("Authentication refused");
1362 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1363 logevent("Received disconnect request");
1364 ssh_state
= SSH_STATE_CLOSED
;
1366 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1367 fatalbox("Strange packet received, type %d", pktin
.type
);
1371 logevent("Authentication successful");
1376 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1381 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1384 if (ssh_state
== SSH_STATE_CLOSED
)
1388 send_packet(SSH1_CMSG_REQUEST_PTY
,
1389 PKT_STR
, cfg
.termtype
,
1390 PKT_INT
, rows
, PKT_INT
, cols
,
1391 PKT_INT
, 0, PKT_INT
, 0,
1394 ssh_state
= SSH_STATE_INTERMED
;
1395 do { crReturnV
; } while (!ispkt
);
1396 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1397 fatalbox("Protocol confusion");
1398 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1399 c_write("Server refused to allocate pty\r\n", 32);
1401 logevent("Allocated pty");
1404 if (*cfg
.remote_cmd
)
1405 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1407 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1408 logevent("Started session");
1410 ssh_state
= SSH_STATE_SESSION
;
1417 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1418 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1419 long len
= GET_32BIT(pktin
.body
);
1420 c_write(pktin
.body
+4, len
);
1421 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1422 ssh_state
= SSH_STATE_CLOSED
;
1423 logevent("Received disconnect request");
1424 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1425 /* may be from EXEC_SHELL on some servers */
1426 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1427 /* may be from EXEC_SHELL on some servers
1428 * if no pty is available or in other odd cases. Ignore */
1429 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1430 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1432 fatalbox("Strange packet received: type %d", pktin
.type
);
1435 send_packet(SSH1_CMSG_STDIN_DATA
,
1436 PKT_INT
, inlen
, PKT_DATA
, in
, inlen
, PKT_END
);
1444 * Utility routine for decoding comma-separated strings in KEXINIT.
1446 int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1447 int needlen
= strlen(needle
);
1450 * Is it at the start of the string?
1452 if (haylen
>= needlen
&& /* haystack is long enough */
1453 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1454 (haylen
== needlen
|| haystack
[needlen
] == ',')
1455 /* either , or EOS follows */
1459 * If not, search for the next comma and resume after that.
1460 * If no comma found, terminate.
1462 while (haylen
> 0 && *haystack
!= ',')
1463 haylen
--, haystack
++;
1466 haylen
--, haystack
++; /* skip over comma itself */
1471 * SSH2 key creation method.
1473 void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1475 /* First 20 bytes. */
1478 SHA_Bytes(&s
, H
, 20);
1479 SHA_Bytes(&s
, &chr
, 1);
1480 SHA_Bytes(&s
, H
, 20);
1481 SHA_Final(&s
, keyspace
);
1482 /* Next 20 bytes. */
1485 SHA_Bytes(&s
, H
, 20);
1486 SHA_Bytes(&s
, keyspace
, 20);
1487 SHA_Final(&s
, keyspace
+20);
1491 * Handle the SSH2 transport layer.
1493 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1497 static Bignum e
, f
, K
;
1498 static struct ssh_cipher
*cscipher_tobe
= NULL
;
1499 static struct ssh_cipher
*sccipher_tobe
= NULL
;
1500 static struct ssh_mac
*csmac_tobe
= NULL
;
1501 static struct ssh_mac
*scmac_tobe
= NULL
;
1502 static struct ssh_compress
*cscomp_tobe
= NULL
;
1503 static struct ssh_compress
*sccomp_tobe
= NULL
;
1504 static char *hostkeydata
, *sigdata
, *keystr
;
1505 static int hostkeylen
, siglen
;
1506 static unsigned char exchange_hash
[20];
1507 static unsigned char keyspace
[40];
1514 * Construct and send our key exchange packet.
1516 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
1517 for (i
= 0; i
< 16; i
++)
1518 ssh2_pkt_addbyte((unsigned char)random_byte());
1519 /* List key exchange algorithms. */
1520 ssh2_pkt_addstring_start();
1521 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1522 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
1523 if (i
< lenof(kex_algs
)-1)
1524 ssh2_pkt_addstring_str(",");
1526 /* List server host key algorithms. */
1527 ssh2_pkt_addstring_start();
1528 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1529 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
1530 if (i
< lenof(hostkey_algs
)-1)
1531 ssh2_pkt_addstring_str(",");
1533 /* List client->server encryption algorithms. */
1534 ssh2_pkt_addstring_start();
1535 for (i
= 0; i
< lenof(ciphers
); i
++) {
1536 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1537 if (i
< lenof(ciphers
)-1)
1538 ssh2_pkt_addstring_str(",");
1540 /* List server->client encryption algorithms. */
1541 ssh2_pkt_addstring_start();
1542 for (i
= 0; i
< lenof(ciphers
); i
++) {
1543 ssh2_pkt_addstring_str(ciphers
[i
]->name
);
1544 if (i
< lenof(ciphers
)-1)
1545 ssh2_pkt_addstring_str(",");
1547 /* List client->server MAC algorithms. */
1548 ssh2_pkt_addstring_start();
1549 for (i
= 0; i
< lenof(macs
); i
++) {
1550 ssh2_pkt_addstring_str(macs
[i
]->name
);
1551 if (i
< lenof(macs
)-1)
1552 ssh2_pkt_addstring_str(",");
1554 /* List server->client MAC algorithms. */
1555 ssh2_pkt_addstring_start();
1556 for (i
= 0; i
< lenof(macs
); i
++) {
1557 ssh2_pkt_addstring_str(macs
[i
]->name
);
1558 if (i
< lenof(macs
)-1)
1559 ssh2_pkt_addstring_str(",");
1561 /* List client->server compression algorithms. */
1562 ssh2_pkt_addstring_start();
1563 for (i
= 0; i
< lenof(compressions
); i
++) {
1564 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1565 if (i
< lenof(compressions
)-1)
1566 ssh2_pkt_addstring_str(",");
1568 /* List server->client compression algorithms. */
1569 ssh2_pkt_addstring_start();
1570 for (i
= 0; i
< lenof(compressions
); i
++) {
1571 ssh2_pkt_addstring_str(compressions
[i
]->name
);
1572 if (i
< lenof(compressions
)-1)
1573 ssh2_pkt_addstring_str(",");
1575 /* List client->server languages. Empty list. */
1576 ssh2_pkt_addstring_start();
1577 /* List server->client languages. Empty list. */
1578 ssh2_pkt_addstring_start();
1579 /* First KEX packet does _not_ follow, because we're not that brave. */
1580 ssh2_pkt_addbool(FALSE
);
1582 ssh2_pkt_adduint32(0);
1583 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
1586 if (!ispkt
) crWaitUntil(ispkt
);
1587 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
1590 * Now examine the other side's KEXINIT to see what we're up
1593 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
1594 fatalbox("expected key exchange packet from server");
1596 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
1597 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
1598 pktin
.savedpos
+= 16; /* skip garbage cookie */
1599 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
1600 for (i
= 0; i
< lenof(kex_algs
); i
++) {
1601 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
1606 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
1607 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
1608 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
1609 hostkey
= hostkey_algs
[i
];
1613 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
1614 for (i
= 0; i
< lenof(ciphers
); i
++) {
1615 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1616 cscipher_tobe
= ciphers
[i
];
1620 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
1621 for (i
= 0; i
< lenof(ciphers
); i
++) {
1622 if (in_commasep_string(ciphers
[i
]->name
, str
, len
)) {
1623 sccipher_tobe
= ciphers
[i
];
1627 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
1628 for (i
= 0; i
< lenof(macs
); i
++) {
1629 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1630 csmac_tobe
= macs
[i
];
1634 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
1635 for (i
= 0; i
< lenof(macs
); i
++) {
1636 if (in_commasep_string(macs
[i
]->name
, str
, len
)) {
1637 scmac_tobe
= macs
[i
];
1641 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
1642 for (i
= 0; i
< lenof(compressions
); i
++) {
1643 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1644 cscomp_tobe
= compressions
[i
];
1648 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
1649 for (i
= 0; i
< lenof(compressions
); i
++) {
1650 if (in_commasep_string(compressions
[i
]->name
, str
, len
)) {
1651 sccomp_tobe
= compressions
[i
];
1657 * Currently we only support Diffie-Hellman and DSS, so let's
1658 * bomb out if those aren't selected.
1660 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
)
1661 fatalbox("internal fault: chaos in SSH 2 transport layer");
1664 * Now we begin the fun. Generate and send e for Diffie-Hellman.
1667 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
1672 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
1673 fatalbox("expected key exchange packet from server");
1675 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
1676 f
= ssh2_pkt_getmp();
1677 ssh2_pkt_getstring(&sigdata
, &siglen
);
1681 sha_string(&exhash
, hostkeydata
, hostkeylen
);
1682 sha_mpint(&exhash
, e
);
1683 sha_mpint(&exhash
, f
);
1684 sha_mpint(&exhash
, K
);
1685 SHA_Final(&exhash
, exchange_hash
);
1688 debug(("Exchange hash is:\r\n"));
1689 for (i
= 0; i
< 20; i
++)
1690 debug((" %02x", exchange_hash
[i
]));
1694 hostkey
->setkey(hostkeydata
, hostkeylen
);
1695 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20))
1696 fatalbox("Server failed host key check");
1699 * Expect SSH2_MSG_NEWKEYS from server.
1702 if (pktin
.type
!= SSH2_MSG_NEWKEYS
)
1703 fatalbox("expected new-keys packet from server");
1706 * Authenticate remote host: verify host key. (We've already
1707 * checked the signature of the exchange hash.)
1709 keystr
= hostkey
->fmtkey();
1710 verify_ssh_host_key(savedhost
, keystr
);
1714 * Send SSH2_MSG_NEWKEYS.
1716 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
1720 * Create and initialise session keys.
1722 cscipher
= cscipher_tobe
;
1723 sccipher
= sccipher_tobe
;
1726 cscomp
= cscomp_tobe
;
1727 sccomp
= sccomp_tobe
;
1729 * Set IVs after keys.
1731 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
1732 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
1733 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
1734 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
1735 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
1736 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
1739 * Now we're encrypting. Begin returning 1 to the protocol main
1740 * function so that other things can run on top of the
1741 * transport. If we ever see a KEXINIT, we must go back to the
1746 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
1747 goto begin_key_exchange
;
1753 * SSH2: remote identifier for the main session channel.
1755 static unsigned long ssh_remote_channel
;
1758 * Handle the SSH2 userauth and connection layers.
1760 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
1762 static unsigned long remote_winsize
;
1763 static unsigned long remote_maxpkt
;
1768 * Request userauth protocol, and await a response to it.
1770 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
1771 ssh2_pkt_addstring("ssh-userauth");
1773 crWaitUntilV(ispkt
);
1774 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
)
1775 fatalbox("Server refused user authentication protocol");
1778 * FIXME: currently we support only password authentication.
1779 * (This places us technically in violation of the SSH2 spec.
1780 * We must fix this.)
1784 * Get a username and a password.
1786 static char username
[100];
1787 static char password
[100];
1791 if ((flags
& FLAG_CONNECTION
) && !*cfg
.username
) {
1792 c_write("login as: ", 10);
1794 crWaitUntilV(!ispkt
);
1795 while (inlen
--) switch (c
= *in
++) {
1802 c_write("\b \b", 3);
1808 c_write("\b \b", 3);
1817 if (((c
>= ' ' && c
<= '~') ||
1818 ((unsigned char)c
>= 160)) && pos
< 40) {
1819 username
[pos
++] = c
;
1826 username
[strcspn(username
, "\n\r")] = '\0';
1829 strncpy(username
, cfg
.username
, 99);
1830 username
[99] = '\0';
1831 if (flags
& FLAG_VERBOSE
) {
1832 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
1833 c_write(stuff
, strlen(stuff
));
1837 if (!(flags
& FLAG_WINDOWED
)) {
1839 sprintf(prompt
, "%s@%s's password: ", cfg
.username
, savedhost
);
1840 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1842 * get_password failed to get a password (for
1843 * example because one was supplied on the command
1844 * line which has already failed to work).
1847 logevent("No more passwords to try");
1848 ssh_state
= SSH_STATE_CLOSED
;
1852 c_write("password: ", 10);
1856 crWaitUntilV(!ispkt
);
1857 while (inlen
--) switch (c
= *in
++) {
1874 if (((c
>= ' ' && c
<= '~') ||
1875 ((unsigned char)c
>= 160)) && pos
< 40)
1876 password
[pos
++] = c
;
1883 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
1884 ssh2_pkt_addstring(username
);
1885 ssh2_pkt_addstring("ssh-connection"); /* service requested */
1886 ssh2_pkt_addstring("password");
1887 ssh2_pkt_addbool(FALSE
);
1888 ssh2_pkt_addstring(password
);
1891 crWaitUntilV(ispkt
);
1892 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
1893 c_write("Access denied\r\n", 15);
1894 logevent("Authentication refused");
1900 * Now we're authenticated for the connection protocol. The
1901 * connection protocol will automatically have started at this
1902 * point; there's no need to send SERVICE_REQUEST.
1906 * So now create a channel with a session in it.
1908 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
1909 ssh2_pkt_addstring("session");
1910 ssh2_pkt_adduint32(100); /* as good as any */
1911 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big window which we ignore */
1912 ssh2_pkt_adduint32(0xFFFFFFFFUL
); /* very big max pkt size */
1914 crWaitUntilV(ispkt
);
1915 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
1916 fatalbox("Server refused to open a session");
1917 /* FIXME: error data comes back in FAILURE packet */
1919 if (ssh2_pkt_getuint32() != 100) {
1920 fatalbox("Server's channel confirmation cited wrong channel");
1922 ssh_remote_channel
= ssh2_pkt_getuint32();
1923 remote_winsize
= ssh2_pkt_getuint32();
1924 remote_maxpkt
= ssh2_pkt_getuint32();
1925 logevent("Opened channel for session");
1928 * Now allocate a pty for the session.
1930 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1931 ssh2_pkt_adduint32(ssh_remote_channel
); /* recipient channel */
1932 ssh2_pkt_addstring("pty-req");
1933 ssh2_pkt_addbool(1); /* want reply */
1934 ssh2_pkt_addstring(cfg
.termtype
);
1935 ssh2_pkt_adduint32(cols
);
1936 ssh2_pkt_adduint32(rows
);
1937 ssh2_pkt_adduint32(0); /* pixel width */
1938 ssh2_pkt_adduint32(0); /* pixel height */
1939 ssh2_pkt_addstring_start();
1940 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
1943 do { /* FIXME: pay attention to these */
1944 crWaitUntilV(ispkt
);
1945 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1947 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1948 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1949 fatalbox("Server got confused by pty request");
1951 c_write("Server refused to allocate pty\r\n", 32);
1953 logevent("Allocated pty");
1959 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
1960 ssh2_pkt_adduint32(ssh_remote_channel
); /* recipient channel */
1961 ssh2_pkt_addstring("shell");
1962 ssh2_pkt_addbool(1); /* want reply */
1964 do { /* FIXME: pay attention to these */
1965 crWaitUntilV(ispkt
);
1966 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
1967 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
1968 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
1969 fatalbox("Server got confused by shell request");
1971 fatalbox("Server refused to start a shell");
1973 logevent("Started a shell");
1982 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
1983 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1986 if (ssh2_pkt_getuint32() != 100)
1987 continue; /* wrong channel */
1988 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
1989 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
1990 continue; /* extended but not stderr */
1991 ssh2_pkt_getstring(&data
, &length
);
1993 c_write(data
, length
);
1994 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
1995 ssh_state
= SSH_STATE_CLOSED
;
1996 logevent("Received disconnect request");
1997 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
1998 continue; /* exit status et al; ignore (FIXME?) */
1999 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2000 continue; /* ignore for now (FIXME!) */
2002 fatalbox("Strange packet received: type %d", pktin
.type
);
2005 /* FIXME: for now, ignore window size */
2006 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2007 ssh2_pkt_adduint32(ssh_remote_channel
);
2008 ssh2_pkt_addstring_start();
2009 ssh2_pkt_addstring_data(in
, inlen
);
2018 * Handle the top-level SSH2 protocol.
2020 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2022 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2024 do_ssh2_authconn(in
, inlen
, ispkt
);
2028 * Called to set up the connection. Will arrange for WM_NETEVENT
2029 * messages to be passed to the specified window, whose window
2030 * procedure should then call telnet_msg().
2032 * Returns an error message, or NULL on success.
2034 static char *ssh_init (HWND hwnd
, char *host
, int port
, char **realhost
) {
2038 if(crypto_startup() == 0)
2039 return "Microsoft high encryption pack not installed!";
2042 p
= connect_to_host(host
, port
, realhost
);
2047 return "Protocol initialisation error";
2049 if (hwnd
&& WSAAsyncSelect (s
, hwnd
, WM_NETEVENT
, FD_READ
| FD_CLOSE
) == SOCKET_ERROR
)
2050 switch (WSAGetLastError()) {
2051 case WSAENETDOWN
: return "Network is down";
2052 default: return "WSAAsyncSelect(): unknown error";
2059 * Process a WM_NETEVENT message. Will return 0 if the connection
2060 * has closed, or <0 for a socket error.
2062 static int ssh_msg (WPARAM wParam
, LPARAM lParam
) {
2067 * Because reading less than the whole of the available pending
2068 * data can generate an FD_READ event, we need to allow for the
2069 * possibility that FD_READ may arrive with FD_CLOSE already in
2070 * the queue; so it's possible that we can get here even with s
2071 * invalid. If so, we return 1 and don't worry about it.
2073 if (s
== INVALID_SOCKET
)
2076 if (WSAGETSELECTERROR(lParam
) != 0)
2077 return -WSAGETSELECTERROR(lParam
);
2079 switch (WSAGETSELECTEVENT(lParam
)) {
2082 ret
= recv(s
, buf
, sizeof(buf
), 0);
2083 if (ret
< 0 && WSAGetLastError() == WSAEWOULDBLOCK
)
2085 if (ret
< 0) /* any _other_ error */
2086 return -10000-WSAGetLastError();
2091 ssh_gotdata (buf
, ret
);
2092 if (ssh_state
== SSH_STATE_CLOSED
) {
2099 return 1; /* shouldn't happen, but WTF */
2103 * Called to send data down the Telnet connection.
2105 static void ssh_send (char *buf
, int len
) {
2106 if (s
== INVALID_SOCKET
)
2109 ssh_protocol(buf
, len
, 0);
2113 * Called to set the size of the window from Telnet's POV.
2115 static void ssh_size(void) {
2116 switch (ssh_state
) {
2117 case SSH_STATE_BEFORE_SIZE
:
2118 case SSH_STATE_CLOSED
:
2119 break; /* do nothing */
2120 case SSH_STATE_INTERMED
:
2121 size_needed
= TRUE
; /* buffer for later */
2123 case SSH_STATE_SESSION
:
2125 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2126 PKT_INT
, rows
, PKT_INT
, cols
,
2127 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2133 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2134 * can send an EOF and collect resulting output (e.g. `plink
2137 static void ssh_special (Telnet_Special code
) {
2138 if (code
== TS_EOF
) {
2139 if (ssh_version
= 1) {
2140 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2142 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2143 ssh2_pkt_adduint32(ssh_remote_channel
);
2153 * Read and decrypt one incoming SSH packet.
2154 * (only used by pSCP)
2156 static void get_packet(void)
2158 unsigned char buf
[4096], *p
;
2165 while ((to_read
= s_rdpkt(&p
, &len
)) > 0) {
2166 if (to_read
> sizeof(buf
)) to_read
= sizeof(buf
);
2167 len
= s_read(buf
, to_read
);
2168 if (len
!= to_read
) {
2180 * Receive a block of data over the SSH link. Block until
2181 * all data is available. Return nr of bytes read (0 if lost connection).
2182 * (only used by pSCP)
2184 int ssh_scp_recv(unsigned char *buf
, int len
)
2186 static int pending_input_len
= 0;
2187 static unsigned char *pending_input_ptr
;
2190 if (pending_input_len
>= to_read
) {
2191 memcpy(buf
, pending_input_ptr
, to_read
);
2192 pending_input_ptr
+= to_read
;
2193 pending_input_len
-= to_read
;
2197 if (pending_input_len
> 0) {
2198 memcpy(buf
, pending_input_ptr
, pending_input_len
);
2199 buf
+= pending_input_len
;
2200 to_read
-= pending_input_len
;
2201 pending_input_len
= 0;
2204 if (s
== INVALID_SOCKET
)
2206 while (to_read
> 0) {
2208 if (s
== INVALID_SOCKET
)
2210 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
) {
2211 int plen
= GET_32BIT(pktin
.body
);
2212 if (plen
<= to_read
) {
2213 memcpy(buf
, pktin
.body
+ 4, plen
);
2217 memcpy(buf
, pktin
.body
+ 4, to_read
);
2218 pending_input_len
= plen
- to_read
;
2219 pending_input_ptr
= pktin
.body
+ 4 + to_read
;
2222 } else if (pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2223 int plen
= GET_32BIT(pktin
.body
);
2224 fwrite(pktin
.body
+ 4, plen
, 1, stderr
);
2225 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2226 logevent("Received disconnect request");
2227 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
||
2228 pktin
.type
== SSH1_SMSG_FAILURE
) {
2230 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2232 sprintf(logbuf
, "Remote exit status: %d", GET_32BIT(pktin
.body
));
2234 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2235 logevent("Closing connection");
2239 fatalbox("Strange packet received: type %d", pktin
.type
);
2247 * Send a block of data over the SSH link.
2248 * Block until all data is sent.
2249 * (only used by pSCP)
2251 void ssh_scp_send(unsigned char *buf
, int len
)
2253 if (s
== INVALID_SOCKET
)
2255 send_packet(SSH1_CMSG_STDIN_DATA
,
2256 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2260 * Send an EOF notification to the server.
2261 * (only used by pSCP)
2263 void ssh_scp_send_eof(void)
2265 if (s
== INVALID_SOCKET
)
2267 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2271 * Set up the connection, login on the remote host and
2272 * start execution of a command.
2273 * Returns an error message, or NULL on success.
2274 * (only used by pSCP)
2276 char *ssh_scp_init(char *host
, int port
, char *cmd
, char **realhost
)
2281 if (crypto_startup() == 0)
2282 return "Microsoft high encryption pack not installed!";
2285 p
= connect_to_host(host
, port
, realhost
);
2292 return "Protocol initialisation error";
2294 /* Exchange keys and login */
2297 if (s
== INVALID_SOCKET
)
2298 return "Connection closed by remote host";
2299 } while (!do_ssh1_login(NULL
, 0, 1));
2301 if (ssh_state
== SSH_STATE_CLOSED
) {
2304 return "Session initialisation error";
2307 /* Execute command */
2308 sprintf(buf
, "Sending command: %.100s", cmd
);
2310 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2315 SOCKET
ssh_socket(void) { return s
; }
2317 Backend ssh_backend
= {